The present invention relates to a seal for protecting items to be maintained secure or in confidence, and a method utilizing the seal; and more particularly, to a seal modification uniquely marking the seal with identification protecting it against tampering or substitution and to utilization of such a seal in preserving the integrity of items in a package. The United States Government has rights in the invention pursuant to Contract No. DE-AC04-76DP00789 between the Department of Energy and Western Electric Company (41CFR.sctn.9-9.109-6(i) (5) (ii) (b)).
Seal tampering indicator devices known to the art normally ensure continued visibility of the opening of a sealed container. A device disclosed in U.S. Pat. No. 3,933,304 typifies this art in a showing of an elongated container whose sealed ends and other parts carry printed matter adapted to be mutilated upon opening of the container.
The detection of attempts at disguising seal tampering is also found treated in the known art as exemplified by the disclosure of U.S. Pat. No. 3,313,052. Disclosed there is the use of a light-polarizing material as an overlay laminated to a backing for protecting the integrity of information carried by the backing and covered by the overlay. Although cuts made to the overlay exposing the information to tampering can be made undetectable to the naked eye by resealing or re-fusing the overlay with heat, properties of the light-polarizing material altered at the sites of intrusion are revealable under a light-polarizing analyzer. However, the resulting product of the patented protective procedures are duplicable, and thus the object of these procedures can be circumvented by repeating such procedures upon a violated backing stripped of its original light-polarizing polarizing overlay.
Thus, in accordance with the present invention it is an object to provide a new and improved security seal overcoming the shortcomings of the prior art as indicated above.
It is a more specific object of the present invention to provide a simplified, low cost security seal wherein the material of enclosure and closure retaining structures accepts verifiable identification markings.
It is a still further object of the present invention to provide an improved technique for verifying the protective competency of a seal.